Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UMass geologist leads team probing Bering Land Bridge

16.08.2002


Researchers from Woods Hole, Scripps oceanographic institutes sail on new Coast Guard ice breaker to study climate, ocean changes



A University of Massachusetts Amherst geoscientist is part of a team of researchers sailing the Bering and Chukchi seas this summer, searching for clues about the sea floor history and the land bridge that once existed between what is now Alaska and Russia. The team will also explore how the disappearance of the land bridge may have affected that region’s climate. Julie Brigham-Grette and colleagues Lloyd Keigwin of Woods Hole Oceanographic Institute and Neal Driscoll of the Scripps Institution of Oceanography are conducting the research in two separate missions on the U.S. Coast Guard Cutter Healy, an ice-breaking vessel. The project is funded by the National Science Foundation’s Office of Polar Programs and is the first coring program on the new ice breaker. The Healy is 420 feet long, or nearly 1.5 times the length of a football field and nearly eight stories high. This summer is the first official science cruise of the ice breaker in American waters.

The five-month mission of the USCGC Healy to the Bering and Chukchi Seas, which includes two other research projects, will mark one of the most comprehensive scientific deployments ever conducted by a Coast Guard icebreaker, said Brigham-Grette. The team is doing a high-tech, seismic mapping of the area’s ocean floor and its shallow sediments, then taking core samples of the sediments. The science team recently returned from the Bering Sea but will reoccupy the ship Aug. 26-Sept. 17 for work in the Chukchi Sea.


"We want to know how quickly the land bridge formed or was flooded with changes in global sea level, cutting off the migration of people and a wide range of plants and animals," said Brigham-Grette. "And we’re looking at the area’s climate history to understand how the ocean and the atmosphere affected the land, and what happened to the watermasses in the region when the land bridge was submerged," she said. "It’s scientifically exciting because it’s interdisciplinary between the three of us as principal investigators. It’s like putting a puzzle together; with each scientist contributing a different but important puzzle piece."

Brigham-Grette’s expertise is in culling ancient climate records from clues embedded in land, lake, and ocean sediment samples going back tens of thousands of years. Keigwin is an expert at interpreting changes in the temperature and water chemistry of ocean water masses and how these changes are related to past climate change using fossils and ocean sediments. Driscoll specializes in interpreting the layering and displacement of rock and sediments, especially in the distribution of sediments in basins and on continental shelves using geophysics.

Brigham-Grette notes that the Bering Strait has actually been submerged dozens of times, as the glaciers approached and retreated. The submerged subcontinent is known as Beringia. The scientific team hopes to gain an understanding of the paleooceanographic history of the region since the last submergence of the strait, at the end of the last Ice Age, some 20,000 years ago.

When the glaciers melted and the sea level rose, seawater drowned ancient rivers and tundra, creating salty estuaries, Brigham-Grette explained. The seismic exploration led by Driscoll and his students in the Chukchi Sea will locate channels where freshwater rivers once ran, and sediment cores drilled in those areas should offer clues to how quickly the sea level rose. Clues in the layers of deposited mud and silt include fossils and the remains of microscopic plants and animals, such as diatoms (made of silica) and foraminifera (made of carbonate). UMass Amherst graduate student Zach Lundeen, and Woods Hole researchers working with Keigwin will be analyzing the sediments and fossil remains.

"We know the climate was different here back then," said Keigwin. "We hope we can learn how different it was, and how the ocean and atmosphere responded to change. In addition to marine sediments, we hope to get samples of the soils and vegetation that existed on the land bridge. We should be able to learn a lot about how things changed here over time by examining the entire region as an environmental system."

"We are thrilled with the performance of the Healy because this was the first cruise to seismically map the Bering Sea and obtain high resolution sediment cores through the Holocene," said Jane Dionne, program manager for the Arctic Natural Sciences, part of the Office of Polar Programs at the NSF. "This research should greatly advance our understanding of the region and should provide important answers to old questions about the role of the North Pacific in the world circulation system, especially during the past glacial periods."

There is much to be learned about how the Earth works by studying climate change recorded in layers of sediment in the past, says Brigham-Grette. "It’s as if the Earth and its oceans have already run a number of natural experiments in global change for us. It’s our obligation now to read the results of these experiments in the sediments, so that we can use this information to predict the nature of climate change into the future."


Note: Julie Brigham-Grette can be reached at 413/545-4840 or juliebg@geo.umass.edu until Aug. 24.

Elizabeth Luciano | EurekAlert!
Further information:
http://www.geo.umass.edu/beringia/index.html
http://www.uscg.mil/pacarea/healy/

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>